All Questions

59
votes
7answers
160k views

What is the recommended way to safely store Ether?

There are several options for storing Ether : Accounts Mist/Geth accounts. Paper wallets. Icebox Air gapped offline signing of transactions Wallet Mist Multi-signature. In short there are a lot ...
2
votes
1answer
236 views

Is the address under the Ethbase account in mist a public address?

Is the address under the Ethbase account in mist a public address? If so, how do I find the related private key?
29
votes
3answers
7k views

Difference between Memory and Storage?

What is the difference between Memory and Storage ? From both the EVM point of view and the contract design one. Thanks!
10
votes
2answers
4k views

Can I run a website 'on' ethereum or only 'with' ethereum?

Do you run a website 'on' ethereum or 'with' ethereum and if the latter, is that only with 'nodejs'?
18
votes
1answer
3k views

Difference between a pruned and unpruned blockchain

At the Berlin Blockchain Meetup, Gustav Simonsson teased the Homestead release coming soon (tm) and we were discussing blockchain bloat and the current size of the Ethereum blockchain. We discussed ...
5
votes
1answer
2k views

Is there a Javascript client for Ethereum, like Geth?

Ethereum's Github has ethereumjs-lib. It appears to be a collection of modules, but is it also a client like Geth? If so, how can one run this Javascript client?
6
votes
3answers
3k views

web3 methods not implemented

I'm running a geth node on the testnet and trying to run web3.js method from my node server code. Here's my code var Web3 = require("web3"); var web3 = new Web3(new Web3.providers.HttpProvider('http:...
4
votes
0answers
358 views

How many ethers will ever exist? [duplicate]

What is the total number of ethers that will be generated/mined? See https://forum.ethereum.org/discussion/1451/how-many-ethers-will-ever-exist
6
votes
1answer
265 views

Is there a way to interchange between the Mist wallet and geth without having to redownload the whole blockchain?

I already have the ethereum wallet running on my laptop, when I exit it and go to run geth in terminal it redownloads the entire blockchain again? Same thing happens when I go from geth to the wallet. ...
9
votes
3answers
2k views

What's the fastest way to mine a transaction so I can test contracts quickly?

I am developing a solidity automated test framework in nodejs that uses events/logging extensively. The use of events eliminates (I believe) all the RPC simulators out there. It's also frustrating ...
4
votes
2answers
2k views

Unlocking accounts for a back office app

I'm writing a "back office" app and need a way to unlock an account in an automated fashion. Yes, I know security of nodejs is questionable, but there are ways of solving this. blocking web3 from ...
6
votes
2answers
956 views

Ethereum fork of OpenBazaar

Is anyone forking OpenBazaar for Ethereum? OpenBazaar is a Bitcoin marketplace, and the OpenBazaar developers have expressed no interest to integrate any currencies other than Bitcoin.
5
votes
1answer
2k views

Making web3.js work from node server code

I'm running a geth node on the testnet and trying to run web3.js method from my node server code. var coinbase = web3.eth.coinbase; console.log(coinbase); However, I'm getting a provider not set or ...
2
votes
2answers
3k views

How can i sent ETH from a contract wallet to another account?

Use the mist wallet 0.3.9. The ETH from a pool is sent to a wallet address. How can I send the ETH from wallet to account? When I try to send from the wallet address to an exchange address, I saw ...
7
votes
2answers
3k views

How can ethereum be used to send messages between connected machines?

I want to know how I can send messages between accounts and contracts. The idea is that I have three Raspberry Pi devices. Each one is connected to an object (the first to a temperature sensor, the ...
8
votes
2answers
2k views

Why do we have Ethereum mining pools?

When Ethereum wasn't even launched, I remember Vitalik saying that the Ethereum mining process was designed in such a way to prevent the formation of mining pools. (I vaguely remember the reasoning ...
3
votes
1answer
215 views

What (if anything) in Bitcoin is better than Ether in the application area of a payment system? [duplicate]

I know of course that there is much more about Ethereum being a smart contract platform. I only refer to the characteristics of a cryptocurrency. If Ether is used for plain payment purposes similar to ...
2
votes
2answers
509 views

How can I program my DApp to tell my user that their action/transaction has been confirmed?

Take an example of a voting DApp. A user clicks on a vote button, then behind the scenes the transaction containing the vote gets mined on the blockchain. The DApp then wants to alert('You have ...
28
votes
4answers
3k views

How can a DApp detect a fork or chain reorganization using web3.js or additional libraries?

Take an example of a voting DApp. A user clicks on a vote button, then behind the scenes a transaction gets mined on the blockchain, and finally the DApp tells the user their vote has been recorded. ...
4
votes
1answer
261 views

EtherEx decentralized exchange

Been waiting for a long time to be able to access a decentralized exchange. When will EtherEx be launched and will it support BTC ETH pair?
14
votes
5answers
4k views

How do I know when I've run out of gas programmatically?

This keeps coming up on the gitter forums so I thought I'd ask and answer this question: How do you know when you've run out of gas?
17
votes
5answers
36k views

How to know if a transaction went through or not? (out of gas)

Apparently when sending transactions from an Account instead of a Wallet, the gas spent is small (21K), and not enough to send ether to a Contract Wallet (out of gas, so to speak). When this happens, ...
20
votes
2answers
5k views

What is an Enode ID in Ethereum?

What is the definition of an Enode ID or Enode URI? What is it used for and how is it made?
6
votes
1answer
2k views

How to find the number of unconfirmed transactions?

Bitcoin has a mempool with unconfirmed transactions. Where can I find statistics on the size of Ethereum's mempool of unconfirmed transactions?
3
votes
2answers
3k views

Where can I find transactions per second statistics?

A few days ago Vitalik claimed Ethereum was doing 8 transactions per second. The tweet linked to Etherchain, which doesn't seem to have a transactions per second graph. Where can I find an Ethereum ...
15
votes
3answers
5k views

How does the Ethereum ETH accounting system work and prevent double-spends?

In Bitcoin, the BTC accounting system is based on UTXOs (Unspent Transaction Outputs), which prevents the same BTC from being spent multiple times. I heard that Ethereum has a simpler account balance ...
2
votes
1answer
490 views

Subcurrency Example: Why always be the “minter” using browser compiler?

A note in the docs referring to the contract example SubCurrency states: This is not a nice example for browser-solidity. If you use browser-solidity to try this example, you cannot change the ...
7
votes
1answer
350 views

Why is homebrew downloading old geth version?

Im on mac OSX, so I go to terminal CLI and do brew install ethereum then I get ==> Downloading https://build.ethdev.com/builds/OSX%20Go%20master%20brew/193/bottle/ethereum-1.1.0.yosemite.bottle....
92
votes
2answers
85k views

What is Geth's “fast” sync, and why is it faster?

One of the answers to this question suggested using Geth's --fast flag to help quickly synchronise the block data. How does the flag work, and how does using it speed up the synchronisation? Are we ...
9
votes
2answers
6k views

Corruption on data-block while synchronising

My home server's been down for a couple of days while I do some upgrades. I'd had Geth running in one of the terminal windows, but shut it down gracefully using exit before taking the server offline. ...
5
votes
4answers
788 views

What is Etherparty?

Etherparty is a platform that removes the complexity and management of creating and executing smart contracts. What exactly does that mean, and how does that work?
5
votes
2answers
771 views

Is it recommended to run Ethereum supernodes?

In the early days of bitcoin there was a demand for system administrators who were able to run supernodes to support the network with stable nodes and high bandwidth. Litecoin is still recommending ...
4
votes
1answer
145 views

What is the C-Like Language CLL?

There are some older projects, dated back to 2014 which develop contracts in CLL, C-Like Language. What is this and is this still being developed/used?
13
votes
3answers
2k views

What design patterns are appropriate for data structure modification within Ethereum smart contracts?

I am looking to hear about design patterns that people have implemented within Ethereum smart contracts to allow for post deploy modification of data structures. For example, say I have a contract ...
7
votes
1answer
644 views

What is “Universal Hash Time”?

What is "Universal Hash Time" which is presented by Jeff Coleman at DEVCON1? What is the purpose? What is the problem it will solve? What is the solution? How does it work?
9
votes
1answer
609 views

What data will zk-SNARKs protect?

Implementing zk-SNARKs is planned in Ethereum roadmap, what data will be obfuscated? transaction sender and receiver? data in transactions? data stored in contracts? variables and methods in ...
5
votes
1answer
747 views

Why is fast sync not working with geth 1.1?

When I run geth --fast I get: Incorrect Usage. geth [global options] command [command options] [arguments...] VERSION: 1.1.0 [...] flag provided but not defined: -fast How do I fix this?
4
votes
1answer
800 views

How can I check which network I'm working on?

When I start eth I get the following header: $ eth (++)Ethereum Beware. You're entering the Frontier! [...] I think i followed the instructions for working on a private network (because i just want ...
3
votes
1answer
118 views

Potential security issues warning banners with Ethereum

I'm testing ethereum and the foundation websites states that Frontier is an early access to the Ethereum network. Bugs and security issues might be present. Before downloading you have to agree ...
1
vote
0answers
83 views

Why is my node taking so long to sync? [duplicate]

I downloaded the ethereum wallet, and its taken a few days yet its still syncing. Im on block ~701,000 thus far. Is something wrong? Is it supposed to take this long?
7
votes
2answers
739 views

Can I compile a smart contract without removing the line breaks?

According to an official document, compiling a smart contract needs to remove all the line-breaks in the contract's source-code: If you have the SolC Solidity Compiler installed, you need now ...
7
votes
1answer
1k views

Does a mining reward transaction have a hash?

I can't find a mining reward transaction hash for a given block. I can see the block hash, all the transactions inside the block, etc. But the mining reward transaction is not listed among the details....
15
votes
5answers
16k views

Is there a C# implementation available for Ethereum?

Is there a C# / .NET / Mono implementation available for Ethereum to interact with nodes and/or the blockchain?
14
votes
4answers
5k views

How do Ethereum clients generate unique addresses?

How do Ethereum clients, like Ethereum Wallet or Eth-Lightwallet, generate unique addresses that haven't been used before, and what is the likelihood that these addresses have been used?
15
votes
2answers
4k views

Is it safe to reuse Ether addresses?

I believe it's viewed as unsafe in Bitcoin because of the way transactions are signed. Is this also true for Ether addresses?
16
votes
2answers
21k views

Can I set the gas price to whatever I want?

The default gas price is 0.02e12 Wei. But while creating transactions on the command line or Geth's Javascript console you can define your own gasPrice: web3.eth.sendTransaction({/* ... */, gasPrice: ...
3
votes
1answer
171 views

What options are suitable for Ethereum addresses with checksums?

Since Ethereum addresses don't have checksums, should ICAP addresses (which do have a checksum) be proliferated? Or are there other options more suitable for the proliferation of checksummed ...
37
votes
2answers
21k views

Is there a limit for transaction size?

Is there a theoretical limit for transaction data size when you send a transaction to Ethereum network? Ref. Is there a (theoretical) limit for amount of data that a contract can store?
7
votes
1answer
2k views

How can Hooked-Web3-Provider and Lightwallet work together?

Does anyone know some good working examples of the Eth-Lightwallet and the Hooked-Web3-Provider working together? I was trying to get https://github.com/ConsenSys/eth-lightwallet/blob/master/example/...
11
votes
4answers
2k views

Can there only be one instance of a contract?

Say we have: contract TestFooContract{ //bunch of stuff and state } Does this mean that there is only 1 "TestFooContract"? Or can I instantiate 10 of them? What if I want multiple of these contracts?...

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